Most back pain is caused by disorders of the spine and the joints, muscles, ligaments, and nerve roots around it or the disks between vertebrae. Often, no single specific cause can be identified. Any painful disorder of the spine may cause reflex tightening (spasm) of muscles around the spine.
Arthritis is the swelling and tenderness of one or more joints. The main symptoms of arthritis are joint pain and stiffness, which typically worsen with age. The most common types of arthritis are osteoarthritis and rheumatoid arthritis.